TBSS 402 LS2 build
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
What Gears & Stall RPM are you using?
I suspect the use of the LSXRT Intake allows for another ~4* intake duration VS car intake, but that is just a guess.
Looking forward to your build & results. You choose the right Heads and person to spec IMO.
Good Luck
I suspect the use of the LSXRT Intake allows for another ~4* intake duration VS car intake, but that is just a guess.
Looking forward to your build & results. You choose the right Heads and person to spec IMO.
Good Luck
Alright guys I have one concern now. Decided to calculate my dynamic compression ratio now that I have cam specs and unless I'm doing something wrong I come up with 9.19:1 which is not pump gas friendly correct? This was supposed to be a 93 pump gas build. I haven't talked to Tony yet as it's the weekend and God knows he should have some time off. Would this concern you guys? I know I could always pull timing but that defeats the purpose of going all out with this build if it's costing power anyways.
Don't know how I've missed this thread. Definitely gonna sub it though. FWIW, I ran your numbers and your DCR is fine. The only thing I guessed at was your head gasket bore at 4.1" and the ramp rate of your cam, so if either is incorrect, please tell me.
SCR -- 11.75x
DCR - 8.23 assuming a 54 degree ramp rate (that's your duration at 006 minus your duration at 050)
DCR - 8.49 assuming a 48 degree ramp rate.
I'm the crazy guy who would say you could bump your compression to 12.2 and still run 93. And I'm the even crazier guy who would do it, too.
Also, fwiw, I like the low split on that cam. I think you'll have a ton of midrange. Also, nice job on the lift. That'll help a lot too with the extra lobe area.
SCR -- 11.75x
DCR - 8.23 assuming a 54 degree ramp rate (that's your duration at 006 minus your duration at 050)
DCR - 8.49 assuming a 48 degree ramp rate.
I'm the crazy guy who would say you could bump your compression to 12.2 and still run 93. And I'm the even crazier guy who would do it, too.
Also, fwiw, I like the low split on that cam. I think you'll have a ton of midrange. Also, nice job on the lift. That'll help a lot too with the extra lobe area.
Don't know how I've missed this thread. Definitely gonna sub it though. FWIW, I ran your numbers and your DCR is fine. The only thing I guessed at was your head gasket bore at 4.1" and the ramp rate of your cam, so if either is incorrect, please tell me.
SCR -- 11.75x
DCR - 8.23 assuming a 54 degree ramp rate (that's your duration at 006 minus your duration at 050)
DCR - 8.49 assuming a 48 degree ramp rate.
I'm the crazy guy who would say you could bump your compression to 12.2 and still run 93. And I'm the even crazier guy who would do it, too.
Also, fwiw, I like the low split on that cam. I think you'll have a ton of midrange. Also, nice job on the lift. That'll help a lot too with the extra lobe area.
SCR -- 11.75x
DCR - 8.23 assuming a 54 degree ramp rate (that's your duration at 006 minus your duration at 050)
DCR - 8.49 assuming a 48 degree ramp rate.
I'm the crazy guy who would say you could bump your compression to 12.2 and still run 93. And I'm the even crazier guy who would do it, too.
Also, fwiw, I like the low split on that cam. I think you'll have a ton of midrange. Also, nice job on the lift. That'll help a lot too with the extra lobe area.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thinking about putting a GZ Sportsman Vacuum pump on this engine. Do you guys think it would be beneficial at all? I'm not 100% on the ring gap, my papers are at home right now but I know they're 1.2, 1.2, 3mm rings. Obviously keeping the engine clean inside is a big priority but I'd love to see 10-15 hp from the pump as well. I haven't talked to GZ to see if they have something that will work with my accessories but I can swap the 5th gen LS3 accessories as well. Also considering a Meziere 329 water pump, pricey for what it is though.
Talked to Tony the other night and got the intake and porting started for that as well as the NW 103. Just waiting on the heads to come in so he can work his magic on them. I believe another 6 weeks out though.
Talked to Tony the other night and got the intake and porting started for that as well as the NW 103. Just waiting on the heads to come in so he can work his magic on them. I believe another 6 weeks out though.
On a street car/truck, i would pass on the vacuum pump and the elec water pump. You are better off just putting an underdrive crank pulley/good catch can setup on it and go that route. Way more reliable, speaking from experience. I would upgrade the radiator for sure. DM me if you need a recommendation. Beyond that, weight reduction. I would do a bunch of research on the converter, also. Weight savings/power to be had there, also.
On a street car/truck, i would pass on the vacuum pump and the elec water pump. You are better off just putting an underdrive crank pulley/good catch can setup on it and go that route. Way more reliable, speaking from experience. I would upgrade the radiator for sure. DM me if you need a recommendation. Beyond that, weight reduction. I would do a bunch of research on the converter, also. Weight savings/power to be had there, also.
Personally I would eliminate the PCV and just run a vented catch can. Don’t waste your time with catch cans and pulling it back into the engine.
Run the AN line to the vacuum pump uphill as much as possible so any oil sucked up will drain back and not run toward the pump. Do not tap into the valley cover - even with extensive baffling added the thing pumped oil like crazy. Using the oil fill port on the stock valve cover is pretty good. The motion race works baffled breather port looks really trick. They designed it for race week guys doing a ton of miles.
Run the AN line to the vacuum pump uphill as much as possible so any oil sucked up will drain back and not run toward the pump. Do not tap into the valley cover - even with extensive baffling added the thing pumped oil like crazy. Using the oil fill port on the stock valve cover is pretty good. The motion race works baffled breather port looks really trick. They designed it for race week guys doing a ton of miles.
Wanted to get your guys thoughts based on reading another thread on here. I ordered new headers as my old SW were too small (1 3/4) and went with ARH 1 7/8 headers with their 3" y pipe. I believe it's 3" pipes merged into a single 3" at the end of the Y. Am I correct in assuming that is too much of a restriction for this engine? I was going to call and see if they could a 3"/3" to 4" outlet at the end of the y pipe.
TECH Fanatic
Joined: Jan 2017
Posts: 1,758
Likes: 442
Wanted to get your guys thoughts based on reading another thread on here. I ordered new headers as my old SW were too small (1 3/4) and went with ARH 1 7/8 headers with their 3" y pipe. I believe it's 3" pipes merged into a single 3" at the end of the Y. Am I correct in assuming that is too much of a restriction for this engine? I was going to call and see if they could a 3"/3" to 4" outlet at the end of the y pipe.
Called ARH and was told they can't/won't put a 3"/3" to 4" y merge on the end of it for me so once it comes in I'll probably just grind the welds off and fit my own piece on the end. As much as I wouldn't mind cutouts, I've just never seen them last and not leak. I don't feel like dealing with it honestly, would much rather deal with fitting 4" piping as there's plenty of room under there.
TECH Fanatic
Joined: Jan 2017
Posts: 1,758
Likes: 442
Called ARH and was told they can't/won't put a 3"/3" to 4" y merge on the end of it for me so once it comes in I'll probably just grind the welds off and fit my own piece on the end. As much as I wouldn't mind cutouts, I've just never seen them last and not leak. I don't feel like dealing with it honestly, would much rather deal with fitting 4" piping as there's plenty of room under there.